Old Spurs never die although these days they might age prematurely, like Kawhi Leonard, who has missed all but nine games with an injury the team doctor cleared him to return from in December.

So much for their little slice of heaven by the Riverwalk where Tim Duncan played 19 seasons, leading the Spurs to their fifth title at 38.

Before this, Spurs always faded away slowly, and gratefully. Tony Parker is in his 17th season at 35. Manu Ginobili, who was 25 when he arrived from Euro-ball, is in his 15th at 40. Both remain in the rotation.

The franchise player is now Leonard – or was before he went on the injured list and disappeared from sight, if not from memory.

Kawhi’s just 26 and, until recently, this was a model Spur who played both ends with a vengeance and didn’t brag, complain or, come right down to it, say much of anything.

The last Spur with a personality he didn’t hide was David Robinson, who was like a 7-foot Sunday School teacher with a sense of humor.

(Duncan had a great sense of humor, too, but in public was more like an undertaker.)

The others were polite but only marginally quotable. That left Coach Gregg Popovich to act as spokesman, which he did eloquently, if grumpily, with special menace to TV people who had to ask and duck.

The Spurs embodied Old School principles, now regarded as quaint with everyone else obliged to accept the braggadocio of the modern Come-Celebrate-the-Wonder-of- Me NBA.

Spurs never copped out or made excuses, as when the Lakers swept them in the 2001 Western Conference finals, winning Games 3 and 4 by 39 and 29 points, respectively, after which Popovich declared, “Custer had no idea. That’s my comment.”

Spurs didn’t do drama. The Lakers were like a bad night at the Kardashians with Kobe Bryant, Shaquille O’Neal and Phil Jackson in a long-running triangular shootout. Popovich ran a totally buttoned-up organization, the price they paid to be all for one and one for all.

By 2005 when they won their fourth title, only Duncan remained from their 1999 championship team and he was already in decline after eight warrior seasons and seven long postseasons (he missed one with an injury).

From 2007-2009, they fell in the first or second round, seemingly finished … before blazing a trail back to the Finals, losing in seven games to Miami in 2013, running over the Heat in six in 2014.

The key was Leonard, a 6-6 forward from San Diego State and King High in Riverside with no shooting range and an uncertain future, acquired in a 2011 draft day deal for George Hill, a Pop favorite who was dealt, nonetheless.

Even for a team known for draft wizardry – getting Parker at No. 28, Ginobili with the next-to last pick of the second round – it turned out to be the coup of coups. Leonard was the personification of the Spur Ideal, the most spectacular player they had ever had. He was also the quietest, which on the scale of normal humans was like being a mummy.

He went from shooting 25 percent from 3-point range in college to 38 percent as an NBA rookie. By year five he was averaging 21 points, shooting 51 percent from the field and 44 percent from the arc.

Like all Spurs from Timmy and the Admiral on down, Leonard was zero maintenance … until the day he wasn’t.

He came to camp last fall with a thigh injury no one knew about. Popovich said he would miss the start of the preseason or a good deal of it.

After a failed attempt at coming back from a thigh injury, the Spurs announced on Jan. 17 that Kawhi Leonard would be out indefinitely. He’s still out, and the Spurs seem to be planning on going forward without him. (AP Photo/Eric Gay)

Instead, Leonard missed the entire preseason and 27 games of the season. Returning on Dec. 12, he still sat out back-to-backs and games with only one day’s rest.

It was still too much. He played nine games before the Spurs announced on Jan. 17 that he was out again, indefinitely.

Then things got as wiggy as they never had before for the Spurs.

On Jan. 21, ESPN scoop-meister Adrian Wojnarowski reported a rift between the team and Leonard and “his camp,” who were described as “distant” and “disconnected” from the team.

Of course, Spurs had never done rifts, nor imagined they could. All denied it, as if in chorus.

Leonard’s uncle/personal manager Dennis Robertson told the San Antonio Express-News: “There is nothing true to that story. Kawhi’s camp and the Spurs are how they’ve always been – doing the right thing for the team and the right thing for Kawhi.”

Another month of the right thing passed with Leonard still out and away from the team.

On Feb. 21, Popovich, trying to make the story go away, said, “I’ll be surprised if he returns this season.”

Feb. 27: Leonard, who had been seeing specialists in New York City, returned to San Antonio.

March 7: Ending a long silence, Leonard said he’d be back “soon” and hoped to remain a Spur after his contract expires in 2019 (“for sure.”)

March 11: ESPN sideline reporter Lisa Salters said Leonard would return March 15 against the Pelicans.

March 15: No Kawhi in sight. No word from his people. Spurs fall to Pelicans 98-93.

March 20: Kawhi suits up! Unfortunately, it’s only for the team picture.

“For me, he’s not coming back,” Ginobili tells the Express-News’ Tom Orsborn, “because it (awaiting his return) is not helping. We fell for it a week ago – again.”

March 24: ESPN’s Wojnarowski reports that Parker ran a players-only meeting the week before when teammates pleaded with Kawhi for clarity, describing it as “tense and emotional at times” as players expressed “frustration and confusion over a growing divide … between Leonard and the Spurs.”

Once more the Spurs denied it, as if in a chorus but not convincingly. Noting Leonard’s “introverted” personality, Ginobili said. “It’s hard when he’s barely been with us the whole season.”

In other words, it’s true, or close enough.

Even Spurs get the blues. It’s part of lasting so long. As for Kawhi, he’ll be along soon. For sure.